18897449 has 2 divisors, whose sum is σ = 18897450. Its totient is φ = 18897448.

The previous prime is 18897391. The next prime is 18897469. The reversal of 18897449 is 94479881.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17372224 + 1525225 = 4168^2 + 1235^2 .

It is an emirp because it is prime and its reverse (94479881) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18897449 is a prime.

It is a super-2 number, since 2×18897449² = 714227157415202, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 18897397 and 18897406.

It is not a weakly prime, because it can be changed into another prime (18897469) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9448724 + 9448725.

It is an arithmetic number, because the mean of its divisors is an integer number (9448725).

Almost surely, 2^18897449 is an apocalyptic number.

It is an amenable number.

18897449 is a deficient number, since it is larger than the sum of its proper divisors (1).

18897449 is an equidigital number, since it uses as much as digits as its factorization.

18897449 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 580608, while the sum is 50.

The square root of 18897449 is about 4347.1196210824. The cubic root of 18897449 is about 266.3592156285.

The spelling of 18897449 in words is "eighteen million, eight hundred ninety-seven thousand, four hundred forty-nine".